<!doctype html>
<html>
	<head>
		<title>网页标题</title>
		<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
		<style type="text/css">
		 *{margin:0 auto}
			#bg{
				margin-top:100px;
				width:600px;
				height:200px;
			}
		</style>
	</head>
	<body>
			
		<div id="bg" >
			<img src="code13.php" id="img"><br>
			<input type="text" name="code" id="t"/>
			<input type="submit" value="提交" onclick="change()"/>
			<script >
				var img=document.getElementById("img");
				var t=document.getElementById("t");
				function change(){
					img.src="code13.php?code="+t.value;
				}
			</script>
		</div>
	</body>
</html>